An X-ray detector typically comprises a scintillator layer which converts incident X-rays into light and a light detection arrangement such as e.g. a CMOS photodetector for detecting the light generated within the scintillator layer and incident on a detection surface of the light detection arrangement.
It has been observed that such X-ray detectors may suffer from phantom images. Therefore, WO 2008/126009 proposes to use a secondary radiation source for irradiating the scintillator layer with a secondary radiation which has a wavelength different from a wavelength of incident X-rays. By irradiating such secondary radiation, the proposed X-ray detector may be capable of producing a spatially more uniform response of the scintillator to incident X-rays. The secondary radiation may be provided using e.g. a luminescence sheet or an LED edge-lit waveguiding plate. In a “back-lit” arrangement, the secondary radiation source may be placed behind the light detection arrangement. In this case, the light detection arrangement should have a transparent carrier substrate. Alternatively, in a “front-lit” arrangement, the secondary radiation source may be placed on top of the scintillator layer. In this case, the secondary radiation source should be substantially transparent for X-rays and robust against this radiation.